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Despite our new understanding, fish are, by far, the most exploited vertebrates on the planet, says biologist Jonathan Balcombe, author of
What a Fish Knows
. Humans kill as many as 2.7 trillion fishes each year—not even counting those caught recreationally and those inadvertently killed as bycatch.

Experiments
have shown that fishes can feel both the sharp initial pain of injury as well as the long-lasting pain that follows, and that they
seek relief
from stress and trauma. Such revelations led the American Veterinary Medical Association
to issue guidelines
in 2013 recommending that fishes should “be accorded the same considerations as terrestrial vertebrates in regard to relief from pain.” But in commercial fishing operations, death is seldom quick and painless.

Fishes caught up in such nets may be crushed by the weight of so many other scaled bodies, or their swim bladders may explode from pressure changes as they are hauled up from oceanic depths. Most often, though, they asphyxiate to death on the boat’s deck. “It’s like taking a cow and drowning it rather than shooting it,” says Bernd Kramer, a professor of animal behavior at the University of Regensburg in Germany. “You wouldn’t do that to a cow, would you?”

Marah Hardt, author of
Sex in the Sea
and research director for Future of Fish, a non-profit dedicated to solving ocean challenges, agrees that there’s often a degree of cognitive dissonance—even from those concerned with other aspects of animal welfare—when it comes to fishes. “Folks are like, ‘I’d never eat a whale, and I don’t eat land animals, but I’m fine with fish,’” she says. “I think people just don’t have enough familiarity with fish, and they certainly don’t understand the diversity and complexity of their behaviors.”

The number one way that people can help fishes is to stop eating them.

While “it’s very easy to forget that every one of those trillions we kill is an individual with feelings and a life they value,” Balcombe continues, there is a small but growing science- and activist-led movement to
raise awareness
about these facts. Balcombe and others ultimately hope that teaching people about the complexity of fishes can inspire appropriate welfare reforms in terms of how we catch and kill them—and to convince some people to give up fishes from their diet entirely.

Indeed, the number one way that people can help fishes is to stop eating them, Balcombe says. While he acknowledges that fishes are a crucial part of millions of people’s diets around the world—many of whom do not have the luxury of choosing which protein they would like to have for dinner—for the rest of us, “We need to stop killing fish, not just from an ethical point of view, but also from a conservation and near-extinction standpoint,” he says.

For those who are concerned but who are not ready to give up sashimi and fillets, Balcombe suggests consulting with lists that rank the least ecologically harmful species to eat, such as Monterey Bay Aquarium’s
Seafood Watch
. The ethics side of things is trickier, though. While there are movements in Europe,
especially Norway
, to implement more humane kill methods for fishes, they are by far exceptions to the rule.

A very limited number of specific fisheries also implement methods that reduce suffering. Bluefin tuna, for example, are sometimes quickly killed by inserting
a metal rod
into their brain (some fishermen, however, prefer to let their bluefin bleed out by slicing the arteries behind their fins). But even the metal rod method is motivated not by compassion but by money. Because bluefin—which are threatened with extinction—are so rare and highly valued, fishermen do everything they can to ensure that stress-related lactic acid does not taint the meat. A quick kill is one way of doing that.

But motivations aside, few other species are treated with any concern.

“What would it take—what information would we need—for us to treat fish more humanely in death?” Hardt says. “These animals can feel pain and distress, and we should acknowledge that.”

Balcombe knows that industry reform is going to be a long, uphill battle, but he believes that it can begin with education of sensitive consumers in North America and Europe. “Almost every vegetarian was once an omnivore, and almost every vegan a vegetarian,” he says. “Those are the people we need to tap first and foremost.”

Read Rachel Nuwer’s reported story on the emotional lives of fish
here
.

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